From 307476565ef6eb368dba0d9848b6d857347149ab Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jouni=20H=C3=B6gander?= Date: Tue, 16 Apr 2024 14:04:14 +0800 Subject: [PATCH] drm/i915/psr: Improve fast and IO wake lines calculation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit BugLink: https://bugs.launchpad.net/bugs/2046315 Current fast and IO wake lines calculation is assuming fast wake sync length is 18 pulses. Let's improve this by checking actual length. Add getter for IO buffer wake time and return 10 us there which was assumed with static 42 us IO wake time. Upcoming patches will extent this for different display versions. Bspec: 65450 v3: - s/get_io_buffer_wake_time/io_buffer_wake_time/ and use it directly in calculation. v2: - rename io_wake_time in if block to io_buffer_wake_time - rename get_io_wake_time to get_io_buffer_wake_time Signed-off-by: Jouni Högander Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20240313133221.868391-3-jouni.hogander@intel.com (cherry picked from commit fe10e7c681a147d4635a83706528d5caf349a978 linux-next) Signed-off-by: Hui Wang Acked-by: Timo Aaltonen Acked-by: Guoqing Jiang Signed-off-by: Roxana Nicolescu --- drivers/gpu/drm/i915/display/intel_psr.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c index b539def62e2a..c8c57b157ae4 100644 --- a/drivers/gpu/drm/i915/display/intel_psr.c +++ b/drivers/gpu/drm/i915/display/intel_psr.c @@ -1127,6 +1127,11 @@ static bool _lnl_compute_alpm_params(struct intel_dp *intel_dp, return true; } +static int io_buffer_wake_time(void) +{ + return 10; +} + static bool _compute_alpm_params(struct intel_dp *intel_dp, struct intel_crtc_state *crtc_state) { @@ -1135,12 +1140,15 @@ static bool _compute_alpm_params(struct intel_dp *intel_dp, u8 max_wake_lines; if (DISPLAY_VER(i915) >= 12) { - io_wake_time = 42; - /* - * According to Bspec it's 42us, but based on testing - * it is not enough -> use 45 us. - */ - fast_wake_time = 45; + int tfw_exit_latency = 20; /* eDP spec */ + int phy_wake = 4; /* eDP spec */ + int preamble = 8; /* eDP spec */ + int precharge = intel_dp_aux_fw_sync_len() - preamble; + + io_wake_time = max(precharge, io_buffer_wake_time()) + preamble + + phy_wake + tfw_exit_latency; + fast_wake_time = precharge + preamble + phy_wake + + tfw_exit_latency; /* TODO: Check how we can use ALPM_CTL fast wake extended field */ max_wake_lines = 12;